It is universally accepted that petroleum as a source of energy has a limited future. Nevertheless, very little progress has been made to find alternative sources of fuel to power internal combustion engines. The effort in the United States has focused primarily on finding ways to decrease rather than eliminate petroleum as the fuel source. In the United States this has boiled down to the use of diesel fuel, propane and "gasohol"--a blend of gasoline and about 10% grain derived ethanol. Although each has certain advantages, because all are petroleum based these approaches obviously beg the basic question of a viable alternative to limited petroleum reserves.
As a practical matter, the only near term commercially feasible alternative sources of fuel for the internal combustion engine are coal and biomass, principally grains. Conversion of coal to methanol and the conversion of biomass to ethanol for use as fuels are well-known. However, neither straight methanol nor straight ethanol can be used as gasoline substitutes without significant modifications to the engine.
Only Brazil has made a national commitment to use straight ethanol from indigenous biomass as an alternate source of fuel for its automobiles and other vehicles. Thus far, the Brazilian effort has failed. One reason is the unanticipated problems encountered in conversion and operation of vehicles powered with straight ethanol.
As far as is known, there has been no significant commitment made to methanol conversion, probably because of the economic limititations flowing from the inherently poor combustion properties of this fuel in comparison to gasoline, for example, see U.S. Pat. Nos. 4,298,351 and 4,386,938 to Earle. These patents disclose.compositions for use as a gasoline substitute wherein the compositions include methanol and peroxides. This mixture is alleged to increase the efficiency over straight methanol to give approximately the same miles per gallon as gasoline. However, this fuel composition suffers from combustion characteristics which produce auto-ignition and accompanying knocking in a conventional gasoline engine. As discussed above, the design of the engine can be changed to overcome these problems. However, to overcome these problems in existing engines, other additives, e.g. water and isopropanol are required. For example, see U.S. Pat. No. 4,298,351, column 2, lines 57-64, and U.S. Pat. No. 4,386,938, column 3, lines 6-12.
U.S. Pat. NO. 4,265,638 to Burke is exemplary of another synthetic fuel formulation which is alleged to be suitable for use as a substitute for gasoline in existing internal combustion engines. The major component of Burke's synthetic fuel is indeed an aliphatic hydrocarbon alcohol containing from two to eleven carbon atoms, isopropyl alcohol being preferred and disclosed in the example. Although this fuel composition contains no gasoline, it does contain a significant amount of a petroleum derived aromatic hydrocarbon, such as xylene. Thus, unlike Earle, the Burke formulation is not totally free of dependence on a petroleum source for all of its components. In addition, Burke, like Earle, requires the presence of water in the fuel formulation. Water is alleged to be a beneficial component in the formulations of Earle and Burke, but it is believed that water is an undesirable element in a fuel for gasoline powered internal combustion engines.